BMW 330I 2018–2020 — technical service bulletin
Bulletin B540819 · NHTSA communication 10174016 · issued Apr 1, 2020
Technical service bulletin
communication type
Structure
component
2018–2020
model years
6
vehicle entries
Official summary
SUNROOF REVERSES WHEN CLOSING: This Service Information Bulletin (Revision 3) replaces SI B54 08 19 dated December 2019. The sunroof reverses direction (anti-traps) just as the sunroof glass meets the wind deflector. The sunroof may not properly initialize as a result.
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.